| In the present work, a counter current salting-out homogenous
liquid–liquid extraction combined with deep eutectic solvent-based
–solidification of floating organic droplet-dispersive liquid–liquid
microextraction has been used for the extraction of some antibiotics
from hamburger and cow liver samples before their quantitative
analysis by ion mobility spectrometry. In this process after removing
the lipid from the sample, a mixture of sodium hydroxide solution
and acetonitrile is added to the sample and the obtained mixture is
vortexed. After that, the supernatant is passed through the glass tube
filled with sodium sulphate. By this action the homogenous state is
broken and the tiny droplets of acetonitrile are separated and collected on top of the tube. The separated acetonitrile is mixed with
newly synthesised choline chloride: pivalic acid deep eutectic solvent
at μL–level and immediately dispersed into deionised water. After
placing the mixture into an ice bath, the solidified drop (extraction
solvent containing the analytes) is removed and injected into ion
mobility spectrometry for quantitative analysis. Under the optimised
extraction conditions, the method revealed good extraction recoveries (67–90%), high enrichment factors (670–900), satisfactory
repeatability (relative standard deviation ≤ 6.2) and low limits of
detection (1.7–2.8 ng g−1
). Finally, the introduced approach was
applied to the analysis of the investigated antibiotics (penicillin G,
oxytetracycline and tilmicosin) in the various hamburger and cow
liver samples marketed in Tabriz, Iran. |